The influence of lead and cadmium will be determined in experimental infections with Staphylococcus aureus, Candida albicans or Listeria monocytogenes. If augmentation of infection is found, specific host defenses will be investigated, including phagocytosis, intracellular killing, leukocyte mobilization and delayed immune mechanisms. The effect of the trace metals on alpha-1-antitrypsin will also be determined in vitro in human blood and in vivo in guinea pigs. Alpha-1- antitrypsin will be purified and lead or cadmium or combinations of the two metals will be added in various dosages to determine whether the metals bind or interfere with alpha-1-antitrypsin. It is hoped thereby to provide data on the mechanisms by which smoking relates to emphysema and to determine whether the emphysema occurring in workers exposed to cadmium relates to the effects of cadmium on alpha-1- antitrypsin.